Set up help needed on a Bass Cat Jaguar

[Jaguar2000]

I guess to start things off I need to give as much info as possible. The boat is a 2000 Bass Cat Jaguar, 20' 3", 93" beam, single console, 2-25 gallon fuel tanks mounted one on each side under the rear deck. There are also 3 batteries, remote oil tank and a 3 bank charger mounted between the tanks. The boat is rated for 285 hp although I have just installed a 98 250 EFI with a 26p Trophy Plus prop. The engine at the time of the first test run was set at 3 1/8" below the pad with no PVS plugs or blow out ring and water pressure at 16 psi at 5650 rpms. If you watch the video you will notice that the engine appears to be sitting low in the water which allows the idle exhaust port to be below the surface. The hole shot sucked which is understandable due to the missing ring and PVS plugs. Top end was 74.2 on the GPS with full fuel tanks, 2 pretty big guys and all of our gear and a 20# anchor. I did not get a chance to run it with less weight during the day but the speeds remained consistant. I purchased the 250 EFI drop on from Shaun, compression on all cylinders is between 103 and 107 on all cylinders. Injectors were cleaned and flowed prior to the drop on being shipped to me and runs great and I want to thank Shaun for that. I did install a short tuner, I have no idea what brand but I am sure that Shaun would know. The reeds are stock for now although I will be installing a set of Chris Carson reeds in the spring. Max rpm according to Merc is 5850 and as I stated I am running 200 under that. Looking for all the help I can get in the set up!:D


http://www.youtube.com/watch?v=jaRnAhPqc_k

[oldgeezer]

I have a similar boat, a 21 XL Magnum Stratos(20 ft 8 inches single console 50 gallon fuel tank under the seats) powered by a Pro XB 250 EFI and 8 inch set back hydraulic JP. I did hear the muffled sound of the exhaust which will cause problems on take off unless you trim the motor out. I would suggest a minimum of eight inches set back with a JP. If you can budget it, try for a hydraulic. Provides ease of set up and allows changing of props with ease. I run a 27 P Predator four blade to 6100 RPM. The prop is not vented but does have a lot of cup and has a prop shaft height of 2 1/8 inches and no difficulty in hole shot. I have tried a 26 Tempest Plus which was a dog out of the hole but would run excellent numbers on the top. I have a 26 Bravo1 with dual PVS holes that is an animal out of the hole and a great fishing prop. Many options out there, but I would start with the JP first. Good luck and ask any more questions. Perhaps I may be able to help. Thanks.

[oldgeezer]

If you have not already done so, might want to visit the owners's forum over at the BassCat site. I am sure someone might be able to help there also.
http://www.basscat.com/ Just a suggestion.

[97 TWISTER]

What are really looking for the boat to do. I had a 98 PanteraII that came with 2.5 200 EFI the boat ran low 70's. I put one of my 260 EFI w/20" OS and a sportmaster with 6" set back and it ran upper 70's. I tried different engine hieght from below the pad to above the pad. I don't much about your motor but I think its a little deep for high speed. Very nice boats nice but they ain't no Allison, I wouldn't expect much more than 70's maybe low 80's if you light. I talked them at Bass Cat, they were very nice but they were a little hesitant to talk to me after I told what motor I was running. I did get out of them that a 26-27 Tempest was consistently a good speed prop. I only owned for a couple months so that is all the info I have. Once again very nice boats and very well built, good luck and have fun.
Jerry

[Jaguar2000]

I knew there was something that I forgot.....the boat does have a 6" manual jackplate that was factory rigged. Twister, I guess what I am loking for is better top end speed without destroying the hole shot totally. Oldgeezer, I am on the Basscat boards (Olddawg) and posed this question several times without much help at all which is why I am here. I do know that weight is an issue so I will have to run with less fuel to see what difference it makes. A hydraulic JP is out of the question at this point until my economy picks up. I don't have a lot of people around here to borrow and try props so choices are slim at this point. Thanks for all of the info.

[oldgeezer]

Bob wrote: "I did install a short tuner, I have no idea what brand but I am sure that Shaun would know." If this is the case, how would you be able to prevent the water line constantly covering the exhaust when idling etc? Or, am I miss understanding? Sounds like a "standard" size tuner might help relieve the exhaust issues? Just a thought though.

[Jaguar2000]

Its a question of the engine being deep in the water, a tuner isn't going to raise the back end of the boat. I guess what I am trying to say is that the change of the tuner didn't change the location of the exhaust outlet in the skirt. It probably did change the pressure but with not understanding outboards I can't say for sure. It was recommended that I not use the Optimax tuner with the EFI due to a possible problem with melting pistons. I have no standard tuner available at this time so other than blocking the open exhaust outlets on the lower unit to increase back pressure I have no other option.

[oldgeezer]

Hi Bob. Here is where I am confused? If I were to shorten the tuner on my 250, and I still wanted to maintain a prop shaft height of say 2 inches, would I not have to lower the motor on the JP since the overall distance has now been shortened? I tried to visualize on my motor, and the only way to maintain the same prop shaft height when using a shortened tuner would be to lower the motor? I then might have further issues of the exhaust being in the water. I hope that I am making sense? Perhaps not? Thanks for the clarification as to I am learning a few things also. Never know enough. I am not questioning whether you needed the tuner change, many more pros know more about that than I will ever will when it comes to matching Opti's mids and EFI/Carb powerhead combinations. Thanks.

[Jaguar2000]

The tuner is internal and is bolted to the exhaust plate under the power head, the mid length stayed the same at 20" it just that the tuner is no longer sealed at the bottom of the lower unit to vent all the exhaust gasses or to build back pressure. The over all heigth or length of the engine didn't change..hope you understand what I am saying.

[oldgeezer]

Understand. Thanks for the clarification.

[Wizard]

The tuner won't have much effect on the power so that's not an issue. You do need more setback. With the weight your carrying the 6" is not enough to leverage the hull at WOT. Add a set of 2" Bob's spacers. They are cheap and easy to install. Then set your propshaft at 2.5" below the pad to start. I'm pretty sure this is close to where you need to be. I had a discussion with Rick Pierce about this while helping another freind set up his Puma. The 26 Trophy is a great prop for your rig. You can get it worked by a good prop guy to lift better. Play with the PVS plugs to adjust your holeshot. With the motor back anothe two inches and the raised an inch you should pick up another 2-300 rpms increasing your top end speed. I think 77-78 is a reasonable expectation but maybe only if your lighter.

Your motor can easily be made more powerful. A set of 300PM heads and ECU's will net you a good increase. Maybe to over 80mph. :cheers:

[lpugh]

Install one pvs solid or very small hole, lift the engine to 2.5 in. Try again, I think you will need some prop work or lower pitch.

[Jaguar2000]

Eric is now offering mods for the 98 ECU and fuel and I might just look for a larger jack plate..maybe hydraulic. With the increase in rpms I can see about prop mods or a different prop. Thanks!!